The following background information is provided to assist the reader in understanding the environment in which the invention will typically be used. The terms used herein are not intended to be limited to any particular narrow interpretation unless stated otherwise in this document.
Semi-trailer trucks are well known throughout the world in which an independent truck trailer can interchangeably be connected to practically any desired truck cab for transporting the trailer and its contents to any desired location.
While the truck cab and truck trailer can take any one of a large variety of different forms and sizes, depending on the intended use and intended load to be transported, the interconnection between the cab and trailer has developed into a uniform standard design so that the cabs and trailer can readily be interchanged according to need. Pursuant to this standard form, the truck cab is normally provided with a chassis structure such that a portion of the truck frame extends rearwardly of the cab with one or more drive axles, upon which wheel and tires are mounted, supporting the truck cab on the road surface under the rearwardly extending portion of the frame structure.
A tiltable, steel disk, commonly referred to as the “fifth wheel”, is horizontally disposed on the upper side of the rearwardly extending frame portion, with the fifth wheel having a diverging “V” slot extending rearwardly from an aperture at the axial center.
Related U.S. Pat. Nos. 6,201,252 and 5,863,060 teach a new and improved mechanism intended to be permanently mounted to the fifth wheel of a truck cab and connected to a release rod thereof for quickly and easily disconnecting a trailer king pin from the fifth wheel of the truck cab.
Namely, the improvement includes an adjustable lever mechanism rigidly and pivotally mounted to the fifth wheel at the first end. The first end is sufficiently curved or bent so it can generally fit closely to a cylindrical side surface of the fifth wheel. The first end of the lever arm is pivotally connected to a mounting bracket that is rigidly attached to the side of the fifth wheel. A slide coupling disposed parallel to the lever arm enables an attachment thereof to the release rod so that the point of attachment moves when the lever is pivoted, thereby permitting the release rod to be pulled straight outward from the fifth wheel without any tendency for bending.
A telescopically adjustable extension arm enables the operator to adjust the length of the lever arm to be appropriate for what is needed to permit him to operate the mechanism without difficulty.
Installation of the mechanism taught by the related U.S. Pat. Nos. 6,201,252 and 5,863,060 requires that a length of a portion of the release rod outwardly extending from the fifth wheel must be maintained within a predetermined range in order to eliminate bending of the release rod during operation. However, it has been found that truck operators modified such original release rods to increase the length of the extended portion in a variety of configurations resulting in such predetermined length exceeding the installation requirements. During such modifications, the eyelet termination of the original release rod was also modified causing difficulties of attaching the mechanism to the release rod.
As the result, the mechanism taught by the related U.S. Pat. Nos. 6,201,252 and 5,863,060 was being improperly installed and while it improved ease of disconnecting a trailer king pin from the fifth wheel of the truck cab it did not prevent bending of the release rod.
Therefore, there is a need to provide an improved fifth wheel king pin release mechanism capable of accommodating various field modifications of the original release rod of the fifth wheel.
It also has been found that, occasionally, the king pin would slide over the fifth wheel during coupling of the cab to the trailer and get lodged outside of the fifth wheel necessitating manual leveling of the fifth wheel in order to move the truck cab forward and repeat coupling with the trailer. Such manual leveling of the fifth wheel typically requires the truck operator to seek help from another person to place a wedge between the fifth wheel and the bottom surface of the trailer body.
It has been additionally observed that truck operators used numerous tools to perform other functions related to operating an articulated semi-trailer truck, such as: determining the amount of fuel in the fuel tank or the amount of air in the tires, straightening nails and screws imbedded in the tires for ease of removal, repositioning airline cable and glad hands, balancing the weight on the truck axels, removing loose stones and debris lodged between the tires and pulling down the tarp straps.